WASHINGTON -- The cable television industry enhanced its reputation for effective lobbying Thursday when the Federal Communications Commission adopted exceptionally tame rules on local regulation of cable prices.

The FCC decided to expand its definition of when a local cable company faces no "effective competition," the standard under which local governments are allowed under federal law to regulate some cable prices.

The new rule defines competition as the presence of at least six broadcast channels, in contrast to the three signals originally proposed in December, or the presence of a rival multi-channel video service.

About 60 percent of cable systems will be exposed to some regulation, but the measure is weaker than the FCC's original proposal and leaves most big-city systems free of restraint.

But by persuading the FCC to weaken the regulation, the cable industry may have been too clever for its own good. The measure is so weak that it is likely to strengthen the position of lawmakers determined to impose far tougher restraints on the industry.

"If the FCC had done something meaningful, it might have tempted more people who are looking for an excuse to do nothing," said Sen. Albert Gore Jr., D-Tenn., sponsor of a bill to re-regulate the cable industry. "This rule is just pitifully weak and meaningless. This gives momentum to the legislation."

To be sure, prospects for new cable regulation remain uncertain, and the Bush administration remains staunchly opposed. The lobbying success could shore up support for a bill that would allow telephone companies to provide cable services, something established cable companies fear.

The phone companies, which have access to huge sums of capital and could refit their sprawling networks to carry television, are at present barred from the cable industry.

From the beginning, the National Cable Television Association has tried to fight restraints with a delicate and often cagey minuet.

It quietly supported a standard requiring the presence of six broadcast channels, but it adamantly fought and defeated an additional test requiring that cable companies sign up no more than half the potential subscribers in its market.

But that was precisely the standard deemed most important by consumer groups and local government officials, who have faced a deluge of complaints from their communities about rising cable prices.